Lifting gear valve arrangement
First Claim
1. A lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit of an agricultural commercial vehicle, comprisinga continuously adjustable directional control valve having a neutral position, the directional control valve forming a metering aperture to which an individual pressure compensator is assigned, via which a pressure medium volume flow flows to a working connection, wherein pressure medium flowing back via another working connection flows off to a low pressure or tank connection via the directional control valve;
- a pressure limiting valve fluidly connected to a working channel between the directional control valve and the working connection, wherein said pressure limiting valve is designed to be adjustable, so that the pressure in said working channel is adapted to be limited to different maximum values as a function of different operating states; and
a control device moving the directional control valve to the neutral position based on response of the pressure limiting valve.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is a lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit with a continuously adjustable directional control valve and with an individual pressure compensator via which a pressure medium volume flow to and from a lifting cylinder of the lifting gear can be controlled. A proportionally adjustable pressure limiting valve is provided in the pressure medium flow path between an outlet connection of the directional control valve and a working connection of the lifting gear valve arrangement, via which the pressure inside this area can be limited to a maximum value. The adjustment of the pressure limiting valve is preferably performed as a function of the operating states of the lifting gear or of the type of add-on unit.
17 Citations
20 Claims
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1. A lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit of an agricultural commercial vehicle, comprising
a continuously adjustable directional control valve having a neutral position, the directional control valve forming a metering aperture to which an individual pressure compensator is assigned, via which a pressure medium volume flow flows to a working connection, wherein pressure medium flowing back via another working connection flows off to a low pressure or tank connection via the directional control valve; -
a pressure limiting valve fluidly connected to a working channel between the directional control valve and the working connection, wherein said pressure limiting valve is designed to be adjustable, so that the pressure in said working channel is adapted to be limited to different maximum values as a function of different operating states; and a control device moving the directional control valve to the neutral position based on response of the pressure limiting valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit of an agricultural commercial vehicle, comprising
a continuously adjustable directional control valve having a floating position, the directional control valve forming a metering aperture to which an individual pressure compensator is assigned, via which a pressure medium volume flow flows to a working connection, wherein pressure medium flowing back via another working connection flows off to a low pressure or tank connection via the directional control valve; -
a pressure limiting valve fluidly connected to a working channel between the directional control valve and the working connection, wherein said pressure limiting valve is designed to be adjustable, so that the pressure in said working channel is adapted to be limited to different maximum values as a function of different operating states; and a control device moving the directional control valve to the floating position based on response of the pressure limiting valve. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification